<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>2_变量与常量</title>
</head>
<body>
<script>
    var a = 10;
    console.log(a);
    a = 20;
    console.log(a);
    a = false;
    console.log(a);
    var a = '你好';
    console.log(a);

    let x = 1;
    x = 6.6;
    console.log(x);
    // let x = true;
    //使用let声明变量不可以重复声明,会报错!
    const b =  1;//常量
    console.log(b);
</script>

</body>
</html>